Group IIA secreted phospholipase A2 is associated with the pathobiology leading to COVID-19 mortality

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Abstract

There is an urgent need to identify cellular/molecular mechanisms responsible for severe COVID-19 progressing to mortality. We initially performed untargeted/targeted lipidomics and focused biochemistry on 127 plasma samples and found elevated metabolites associated with secreted phospholipase A2 (sPLA2) activity and mitochondrial dysfunction in severe COVID-19 patients. Deceased COVID-19 patients had higher levels of circulating, catalytically active sPLA2 Group IIA (sPLA2-IIA), with a median value 9.6-fold higher than mild patients and 5.0-fold higher than severe COVID-19 survivors. Elevated sPLA2-IIA levels paralleled several indices of COVID-19 disease severity (e.g., kidney dysfunction, hypoxia, multiple organ dysfunction). A decision tree generated by machine learning identified sPLA2-IIA levels as a central node in stratifying patients that succumbed to COVID-19. Random forest analysis and LASSO-based regression analysis additionally identified sPLA2-IIA and blood urea nitrogen (BUN) as the key variables among 80 clinical indices in predicting COVID-19 mortality. The combined PLA-BUN index performed significantly better than either alone. An independent cohort (n=154) confirmed higher plasma sPLA2-IIA levels in deceased patients vs. severe or mild COVID-19, with the PLA-BUN index-based decision tree satisfactorily stratifying mild, severe, and deceased COVID-19 patients. With clinically tested inhibitors available, this study supports sPLA2-IIA as a therapeutic target to reduce COVID-19 mortality.

Authors

Justin M. Snider, Jeehyun Karen You, Xia Wang, Ashley J. Snider, Brian Hallmark, Manja M. Zec, Michael C. Seeds, Susan Sergeant, Laurel Johnstone, Qiuming Wang, Ryan Sprissler, Tara F. Carr, Karen Lutrick, Sairam Parthasarathy, Christian Bime, Hao H. Zhang, Chiara Luberto, Richard R. Kew, Yusuf A. Hannun, Stefano Guerra, Charles E. McCall, Guang Yao, Maurizio Del Poeta, Floyd H. Chilton

Basal-epithelial stem cells cross an alarmin checkpoint for post-viral lung disease

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Abstract

Epithelial cells are charged with protection at barrier sites, but whether this normally beneficial response might sometimes become dysfunctional still needs definition. Here we identify a pattern of imbalance marked by basal epithelial cell growth and differentiation that replaces normal airspaces in a mouse model of progressive post-viral lung disease due to Sendai virus. Single-cell and lineage-tracing technologies identify a distinct subset of basal epithelial stem cells (basal-ESCs) that extend into gas-exchange tissue to form long-term bronchiolar-alveolar remodeling regions. Moreover, this cell subset is selectively expanded by crossing a cell growth and survival checkpoint linked to the nuclear-localized alarmin IL-33 that is independent of IL-33-receptor signaling and instead connected to autocrine chromatin accessibility. This mechanism creates an activated stem-progenitor cell lineage with potential for physiological or pathological function. Thus, conditional loss of Il33 gene function in basal epithelial cells disrupts homeostasis of the epithelial barrier at skin and gut sites but also markedly attenuates post-viral disease in the lung based on down-regulation of remodeling and inflammation. We thereby identify a basal-ESC strategy to deploy innate-immune machinery that appears to overshoot the primordial goal of self-defense. The findings reveal new targets to stratify and correct chronic and often deadly post-viral disease.

Authors

Kangyun Wu, Kenji Kamimoto, Yong Zhang, Kuangying Yang, Shamus P. Keeler, Benjamin J. Gerovac, Eugene V. Agapov, Stephen P. Austin, Jennifer Yantis, Kelly A. Gissy, Derek E. Byers, Jennifer Alexander-Brett, Christy M. Hoffmann, Matthew Wallace, Michael E. Hughes, Erika C. Crouch, Samantha A. Morris, Michael J. Holtzman

Randomized controlled trial of fractionated laser resurfacing to aged skin as prophylaxis against actinic neoplasia

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Abstract

BACKGROUND. The loss of insulin-like growth factor-1 (IGF-1) expression in senescent dermal fibroblasts during aging is associated with an increased risk of non-melanoma skin cancer (NMSC). We tested how IGF-1 signaling can influence photocarcinogenesis during chronic UVB exposure to determine if fractionated laser resurfacing (FLR) of aged skin which upregulates dermal IGF-1 levels can prevent the occurrence of actinic keratosis (AK) and NMSC. METHODS. A human skin/immunodeficient mouse xenografting model was used to test the effects of a small molecule inhibitor of the IGF-1 receptor on chronic UVB radiation. Subsequently, the durability of FLR treatment was tested on a cohort of human subjects aged ≥65. Finally, 48 subjects aged 60 and older with considerable actinic damage were enrolled in a prospective randomized clinical trial in which they underwent a single unilateral FLR treatment of one lower arm. Numbers of AKs/NMSCs were recorded on both extremities for up to 36 months in blinded fashion. RESULTS. Xenografting studies revealed chronic UVB treatment with a topical IGF-1R inhibitor resulted in a pro-carcinogenic response. A single FLR treatment was durable in restoring appropriate UVB response in geriatric skin for at least two years. FLR resulted in sustained reduction in numbers of AKs and decreased numbers of NMSC in the treated (24) versus untreated (2) arms. INTERPRETATION. The elimination of senescent fibroblasts via FLR reduced the pro-carcinogenic UVB response of aged skin. Thus, wounding therapies are potentially effective prophylaxis for managing high-risk populations. TRIAL REGISTRATION. ClinicalTrials.gov NCT03906253. FUNDING. National Institutes of Health, Veterans Administration.

Authors

Dan F. Spandau, Roy Chen, Jeffrey J. Wargo, Craig A. Rohan, David Southern, Angela Zhang, Mathew Loesch, Jonathan Weyerbacher, Sunil S. Tholpady, Davina Anne Lewis, Matthew Kuhar, Kenneth Y. Tsai, Amber J. Castellanos, Michael G. Kemp, Michael Markey, Elizabeth Cates, Amy R. Williams, Christina Knisely, Sabina Bashir, Ryan Gabbard, Robert Hoopes, Jeffrey B. Travers

Differential roles of FOXO transcription factors on insulin action in brown and white adipose tissue

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Abstract

Insulin and IGF-1 are essential for adipocyte differentiation and function. Mice lacking insulin and IGF-1 receptors in fat (FIGIRKO) exhibit complete loss of white and brown fat (WAT/BAT), glucose intolerance, insulin resistance, hepatosteatosis, and cold intolerance. To determine the role of FOXO transcription factors in the altered adipose phenotype, we generated FIGIRKO mice with fat-specific knockout of fat-expressed Foxos [Foxo1, Foxo3, Foxo4] (F-Quint KO). Unlike FIGIRKO mice, F-Quint KO mice had normal BAT, glucose tolerance, insulin-regulated hepatic glucose production, and cold tolerance. However, loss of FOXOs only partially rescued subcutaneous WAT and hepatosteatosis, did not rescue perigonadal WAT, or systemic insulin resistance, and led to even more marked hyperinsulinemia. Thus, FOXOs play different roles in insulin/IGF1 action in different adipose depots, being more important in BAT > subcutaneous WAT > visceral WAT. Disruption of FOXOs in fat also leads to a reversal of insulin resistance in liver, but not in skeletal muscle, and an exacerbation of hyperinsulinemia. Thus, adipose FOXOs play a unique role in regulating crosstalk between adipose depots, liver and β-cells.

Authors

Erica P. Homan, Bruna Brasil Brandao, Samir Softic, Abdelfattah El Ouaamari, Brian T. O’Neill, Rohit N. Kulkarni, Jason K. Kim, C. Ronald Kahn

The self-peptide repertoire plays a critical role in transplant tolerance induction

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Abstract

While direct allorecognition underpins both solid organ allograft rejection and tolerance induction, the specific molecular targets of most directly-alloreactive CD8+ T cells have not been defined. In this study, we used a combination of genetically-engineered MHC class I (MHC I) constructs, mice with a hepatocyte-specific mutation in the class I antigen-presentation pathway and immunopeptidomic analysis to provide definitive evidence for the contribution of the peptide cargo of allogeneic MHC I molecules to transplant tolerance induction. We established a systematic approach for the discovery of directly-recognised pMHC epitopes, and identified 17 strongly immunogenic H-2Kb-associated peptides recognised by CD8+ T cells from B10.BR (H-2k) mice, 13 of which were also recognised by BALB/c (H-2d) mice. As few as five different tetramers used together were able to identify a high proportion of alloreactive T cells within a polyclonal population, suggesting that there are immunodominant allogeneic MHC-peptide complexes that can account for a large component of the alloresponse.

Authors

Eric T. Son, Pouya Faridi, Moumita Paul-Heng, Mario L. Leong, Kieran English, Sri H. Ramarathinam, Asolina Braun, Nadine L. Dudek, Ian E. Alexander, Leszek Lisowski, Patrick Bertolino, David G. Bowen, Anthony W. Purcell, Nicole A. Mifsud, Alexandra F. Sharland

Functional Th1-oriented T follicular helper cells that infiltrate human breast cancer promote effective adaptive immunity

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Abstract

We previously demonstrated that tumor infiltrating lymphocytes (TIL) in human breast cancer sometimes form organized tertiary lymphoid structures (TLS) characterized by CXCL13-producing T follicular helper (Tfh) cells. The present study found that CD4+ Tfh TIL, CD8+ TIL and TIL-B, co-localizing in TLS, all express the CXCL13 receptor CXCR5. An ex vivo functional assay determined that only activated, functional Th1-oriented Tfh TIL (PD-1hiICOSint phenotype) provide help for immunoglobulin and IFNγ production. A functional Tfh TIL presence signals an active TLS, characterized by humoral (immunoglobulins, Ki-67+ TIL-B in active germinal centers) and cytotoxic (GZMB+CD8+ and GZMB+CD68+ TIL plus Th1 gene expression) immune responses. Analysis of active versus inactive TLS in untreated patients revealed the former are associated with positive clinical outcomes. TLS also contain functional T follicular regulatory (Tfr) TIL, which are characterized by a CD25+CXCR5+GARP+FOXP3+ phenotype and a demethylated FOXP3 gene. Functional Tfr inhibited functional Tfh activities via a GARP-associated TGFβ-dependent mechanism. The activity of tumor-associated TLS was dictated by the relative balance between functional Tfh TIL and functional Tfr TIL. These data provide mechanistic insight into TLS processes orchestrated by functional Th1-oriented Tfh TIL, including TIL-B and CD8+ TIL activation and immunological memory generation. Tfh TIL, regulated by functional Tfr TIL, are an expected key target of PD-1/PD-L1 blockade.

Authors

Grégory Noël, Mireille Langouo Fontsa, Soizic Garaud, Pushpamali De Silva, Alexandre de Wind, Gert G. Van den Eynden, Roberto Salgado, Anaïs Boisson, Hanne Locy, Noémie Thomas, Cinzia Solinas, Edoardo Migliori, Celine Naveaux, Hugues Duvillier, Sophie Lucas, Ligia Craciun, Kris Thielemans, Denis Larsimont, Karen Willard-Gallo

Intravenous bamlanivimab use associates with reduced hospitalization in high-risk patients with mild to moderate COVID-19

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Abstract

BACKGROUND. Clinical data to support the use of bamlanivimab for the treatment of outpatients with mild to moderate coronavirus disease-19 (COVID-19) is needed. METHODS. 2,335 patients who received single-dose bamlanivimab infusion between November 12, 2020 to February 17, 2021 were compared with a propensity-matched control of 2,335 untreated patients with mild to moderate COVID-19 at Mayo Clinic facilities across 4 states. The primary outcome was the rate of hospitalization at days 14, 21 and 28. RESULTS. The median age of the population was 63; 47.3% of the bamlanivimab-treated cohort were ≥65 years; 49.3% were female. High-risk characteristics included hypertension (54.2%), body mass index ≥35 (32.4%), diabetes mellitus (26.5%), chronic lung disease (25.1%), malignancy (16.6%), and renal disease (14.5%). Patients who received bamlanivimab had lower all-cause hospitalization rates at days 14 (1.5% vs 3.5%; Odds Ratio [OR], 0.38), 21 (1.9% vs 3.9%; OR, 0.46), and 28 (2.5% vs 3.9%; OR, 0.61). Secondary exploratory outcomes included lower intensive care unit admission rates at days 14 (0.14% vs 1%; OR, 0.12), 21 (0.25% vs 1%; OR: 0.24) and 28 (0.56% vs 1.1%; OR: 0.52), and lower all-cause mortality at days 14 (0% vs 0.33%), 21 (0.05% vs 0.4%; OR,0.08) and 28 (0.11% vs 0.44%; OR, 0.01). Adverse events were uncommon with bamlanivimab, occurring in 19/2355, most commonly fever (n=6), nausea (n=5), and lightheadedness (n=3). CONCLUSIONS. Among high-risk patients with mild to moderate COVID-19, treatment with bamlanivimab was associated with a statistically significant lower rate of hospitalization compared with usual care. FUNDING. Mayo Clinic.

Authors

Ravindra Ganesh, Colin F. Pawlowski, John C. O'Horo, Lori L. Arndt, Richard F. Arndt, Sarah Bell, Dennis M. Bierle, Molly Destro Borgen, Sara Hanson, Alexander Heyliger, Jennifer L. Larsen, Patrick J. Lenehan, Robert Orenstein, Arjun Puranik, Leigh L. Speicher, Sidna M. Tulledge-Scheitel, AJ Venkatakrishnan, Caroline G. Wilker, Andrew D. Badley, Raymund R. Razonable

Association of in-hospital use of ACE-I/ARB and COVID-19 outcomes in African American population

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Abstract

BACKGROUND. The angiotensin-converting enzyme (ACE) D allele is more prevalent among African Americans (AA) compared to other races/ethnicities and has previously been associated with severe COVID-19 pathogenesis through excessive ACE1 activity. Angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACE-I/ARB) may counteract this mechanism, but their association with COVID-19 outcomes has not been specifically tested in the AA population. METHODS. We identified 6,218 patients who were admitted into Mount Sinai hospitals with COVID-19 between February 24 and May 31, 2020 in the New York City. We evaluated whether the outpatient and in-hospital use of ACE-I/ARB is associated with COVID-19 in-hospital mortality in AA compared with non-AA population. RESULTS. Of the 6,218 COVID-19 patients, 1,138 (18.3%) were ACE-I/ARB users. In a multivariate logistic regression model, ACE-I/ARB use was independently associated with reduced risk of in-hospital mortality in the entire population (OR, 0.655; 95% CI, 0.505-0.850; P=0.001), AA population (OR, 0.44; 95% CI, 0.249-0.779; P=0.005), and non-AA population (OR, 0.748, 95% CI, 0.553-1.012, P=0.06). In the AA population, in-hospital use of ACE-I/ARB was associated with improved mortality (OR, 0.378; 95% CI, 0.188-0.766; P=0.006) while outpatient use was not (OR, 0.889; 95% CI, 0.375-2.158; P=0.812). When analyzing each medication class separately, ARB in-hospital use was significantly associated with reduced in-hospital mortality in the AA population (OR, 0.196; 95% CI, 0.074-0.516; P=0.001), while ACE-I use was not associated with impact on mortality in any population. CONCLUSION. In-hospital use of ARB was associated with a significant reduction in in-hospital mortality among COVID-19-positive AA patients. FUNDING. None.

Authors

Shilong Li, Rangaprasad Sarangarajan, Tomi Jun, Yu-Han Kao, Zichen Wang, Ke Hao, Emilio Schadt, Michael A. Kiebish, Elder Granger, Niven R. Narain, Rong Chen, Eric E. Schadt, Li Li

ZFP91 disturbs metabolic fitness and antitumor activity of tumor-infiltrating T cells

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Abstract

Proper metabolic activities facilitate T cell expansion and antitumor function; however, the mechanisms underlying disruption of the T cell metabolic programme and function in the tumor microenvironment (TME) remain elusive. Here, we show a Zinc finger protein 91 (ZFP91)-governed mechanism disrupting the metabolic pathway and antitumor activity of tumor-infiltrating T cells. Single-cell RNA sequencing revealed that impairments in T cell proliferation and activation correlated with ZFP91 in tissue samples from colorectal cancer patients. T cell-specific deletion of Zfp91 led to enhanced T cell proliferation and potentiated T cell antitumor function. Loss of ZFP91 increased mammalian target of rapamycin complex 1 (mTORC1) activity to drive T cell glycolysis. Mechanistically, T cell antigen receptor (TCR)-dependent ZFP91 cytosolic translocation promoted protein phosphatase 2A (PP2A) complex assembly, thereby restricting mTORC1-mediated metabolic reprogramming. Our results demonstrate that ZFP91 perturbs T cell metabolic and functional states in the TME and suggest that targeting ZFP91 may improve the efficacy of cancer immunotherapy.

Authors

Feixiang Wang, Yuerong Zhang, Xiaoyan Yu, Xiao-Lu Teng, Rui Ding, Zhilin Hu, Aiting Wang, Zhengting Wang, Youqiong Ye, Qiang Zou

Stromal cell-derived DEL-1 inhibits Tfh cell activation and inflammatory arthritis

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Abstract

The secreted protein DEL-1 regulates inflammatory cell recruitment and protects against inflammatory pathologies in animal models. Here, we investigated DEL-1 in inflammatory arthritis using collagen-induced arthritis (CIA) and collagen Ab-induced arthritis (CAIA). In both models, mice with endothelial-specific overexpression of DEL-1 were protected from arthritis relative to WT controls, while arthritis was exacerbated in DEL-1-deficient mice. Compared to WT controls, mice with collagen VI promoter-driven overexpression of DEL-1 in mesenchymal cells were protected against CIA but not CAIA, suggesting a role for DEL-1 in the induction of the arthritogenic Ab response. Indeed, DEL-1 was expressed in perivascular stromal cells of the lymph nodes and inhibited T follicular helper (Tfh) and germinal center B cell responses. Mechanistically, DEL-1 inhibited dendritic cell-dependent induction of Tfh cells by targeting the LFA-1 integrin on T cells. Overall, DEL-1 restrained arthritis through a dual mechanism, one acting locally in the joints and associated with the anti-recruitment function of endothelial cell-derived DEL-1; the other mechanism acting systemically in the lymph nodes and associated with the ability of stromal cell-derived DEL-1 to restrain Tfh responses. DEL-1 may thus be a promising novel therapeutic for the treatment of inflammatory arthritis.

Authors

Hui Wang, Xiaofei Li, Tetsuhiro Kajikawa, Jieun Shin, Jong-Hyung Lim, Ioannis Kourtzelis, Kosuke Nagai, Jonathan Korostoff, Sylvia Grossklaus, Ronald Naumann, Triantafyllos Chavakis, George Hajishengallis